Wednesday 29 February 2012

Bank IT OFFICER / Specialist Exam PracticePaper -8 (DBMS -Database Management Systems )

1 Consider the join of relation R with a relation S. If R has m tuples and S has n tuples, then the maximum and minimum size of the join respectively are
(A) m+n and 0 (B) m+n and |m-n|
(C) mn and 0 (D) mn and m+n


2 Maximum height of a B+ tree of order m with n key values is
(A) Logm(n) (B) (m+n)/2
(C) Logm/2(m+n) (D) None of these


3 Which one is true statement :
(A) With finer degree of granularity of locking a high degree of concurrency is
possible.
(B) Locking prevents non – serializable schedules.
(C) Locking cannot take place at field level.
(D) An exclusive lock on data item X is granted even if a shared lock is already
held on X.


4 Which of the following statement on the view concept in SQL is invalid?
(A) All views are not updateable
(B) The views may be referenced in an SQL statement whenever tables are
referenced.
(C) The views are instantiated at the time they are referenced and not when they
are defined.
(D) The definition of a view should not have GROUP BY clause in it.


5 Which of the following concurrency control schemes is not based on the serializability property?
(A) Two – phase locking (B) Graph-based locking
(C) Time-stamp based locking (D) None of these .


6 Which of the following is a reason to model data?
(A) Understand each user’s perspective of data
(B) Understand the data itself irrespective of the physical representation
(C) Understand the use of data across application areas
(D) All of the above


7 If an entity can belong to only one lower level entity then the constraint is
(A) disjoint (B) partial
(C) overlapping (D) single


8 The common column is eliminated in
(A) theta join (B) outer joinAC14/AT11
(C) natural join (D) composed join


9 In SQL, testing whether a subquery is empty is done using
(A) DISTINCT (B) UNIQUE
(C) NULL (D) EXISTS


10. Use of UNIQUE while defining an attribute of a table in SQL means that the attribute
values are
(A) distinct values (B) cannot have NULL
(C) both (A) & (B) (D) same as primary key


11 .The cost of reading and writing temporary files while evaluating a query can be reduced
by
(A) building indices (B) pipelining
(C) join ordering (D) none of the above


12. A transaction is in __________ state after the final statement has been executed.
(A) partially committed (B) active
(C) committed (D) none of the above


13. In multiple granularity of locks SIX lock is compatible with
(A) IX (B) IS
(C) S (D) SIX


14. The statement that is executed automatically by the system as a side effect of the
modification of the database is
(A) backup (B) assertion
(C) recovery (D) trigger


15 .The normal form that is not necessarily dependency preserving is
(A) 2NF (B) 3NF
(C) BCNF (D) 4NF


16. A functional dependency of the form x → y is trivial if AC14/AT11 Database Management Systems
9
(A) y ⊆ x (B) y ⊂ x
(C) x ⊆ y (D) x ⊂ y

17. The normalization was first proposed by ______________.
(A) Code (B) Codd
(C) Boyce Codd (D) Boyce


18. The division operator divides a dividend A of degree m+n by a divisor relation B of
degree n and produces a result of degree
(A) m – 1 (B) m + 1
(C) m * m (D) m


19 .Which of the following is not a characteristic of a relational database model?
(A) Table (B) Tree like structure
(C) Complex logical relationship (D) Records


20. Assume transaction A holds a shared lock R. If transaction B also requests for a shared
lock on R.
(A) It will result in a deadlock situation.
(B) It will immediately be rejected.
(C) It will immediately be granted.
(D) It will be granted as soon as it is released by A .


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